The development of a comprehensive gene expression database is essential for the discovery of functions for the estimated 100,000 human genes. The EST (expressed sequence tag) approach to identify gene sequences has already led to the assembly of approximately 50,000 unigenes, transcriptional units defined by overlapping EST sequences. While DNA sequence information is of great importance, knowledge of where each gene is expressed and under what circumstances is an essential next step in functional discovery. In this fast-track SBIR application, OriGene Technologies Inc. proposes to determine the tissue-specific expression profiles of initially 2,000 human unigenes, using a relatively high- throughput approach, and to develop a public database with innovative on- line search capabilities to support the general biomedical research community. This effort is in response to our belief that most functional dissection of genes over the next decade will be by individuals seeking out target genes with specific expression profiles that befit certain developmental, differentiation or disease characteristics. A state-of-the-art gene expression database, that also serves as a one-stop reagent shopping site, will be of singular importance and will be a commercial success. PROPOSED COMMERCIAL APPLICATIONS: What allows the rapid progression to functional discovery of a gene has to be, apart from the DNA sequence, the delineation of its sites of expression. The development of an on-line gene expression database, which also serves as a one-stop shopping site for genomic research reagents, will have wide utilities among investigators in both academia and the private sector. Such a Web site will become a mainstay of the biotechnology industry and an assured commercial success.